1. Field of the Invention
This invention relates to a Coriolis mass flowmeter incorporating a measuring tube for guiding a flowing medium, a first oscillator for vibrating the measuring tube, as well as a first oscillation sensor and a second oscillation sensor for capturing the vibrations of the measuring tube, in which configuration the first oscillator, the first oscillation sensor and the second oscillation sensor are mutually spaced apart in the longitudinal direction of the measuring tube and the first oscillator is activated by an oscillation-stimulating control device.
2. Description of the Prior Art
A Coriolis mass flowmeter of this type has been described in WO 95/16897 A2. The Coriolis mass flowmeter according to that document employs the concept of oscillatory stimulation of the circumference of the measuring tube, producing vibrations that cause the diameter of the measuring tube to undergo vibration-induced geometric variations at least in the vibration-stimulating region. WO 01/92833 A1 describes a Coriolis mass flowmeter with similar stimulation of radial vibration of the measuring tube. As a particular feature of that latter Coriolis mass flowmeter, the wall thickness of the measuring tube is substantially less than the radius of the measuring tube, which greatly facilitates the generation of radial vibrations and the concomitant deformation of the circumferential surface of the measuring tube. Moreover, the length of the measuring tube in that Coriolis mass flowmeter is at least of the same order of magnitude as the radius of the measuring tube. The Coriolis mass flowmeter described in WO 01/92833 A1 thus features a measuring tube which due to its short dimension and its large inner diameter restricts the flow of the medium to a minor extent only, for correspondingly marginal interference with the flow in the pipeline in which the Coriolis mass flowmeter is installed.
The problem with these prior-art Coriolis mass flowmeters, however, is their unsatisfactory attainable measuring accuracy which, in particular, requires frequent recalibration.